What characterizes the storage phase of the micturition cycle?

The storage phase of the micturition cycle is characterized by several key components that allow the bladder to hold urine until it is socially acceptable to void. During this phase, the detrusor muscle, which is the primary muscle of the bladder, relaxes. This relaxation accommodates the filling of the bladder with urine, preventing involuntary contractions that would lead to urination.

In conjunction with the relaxation of the detrusor muscle, there is an increase in the tone of the urethral sphincter. This increased tone is crucial as it helps maintain continence by preventing urine from leaking out of the bladder. Both the detrusor muscle relaxation and the elevated urethral sphincter tone work together to facilitate effective storage of urine.

Therefore, all the mentioned characteristics – the bladder not emptying its contents, the detrusor muscle relaxing, and the increased urethral sphincter tone – are integral features of the storage phase of the micturition cycle. This collaborative action enables the bladder to fulfill its role effectively until the individual decides to initiate urination.